var intToRoman = function(num) {
    const a = [
        [1000, 'M'],
        [900, 'CM'],
        [500, 'D'],
        [400, 'CD'],
        [100, 'C'],
        [90, 'XC'],
        [50, 'L'],
        [40, 'XL'],
        [10, 'X'],
        [9, 'IX'],
        [5, 'V'],
        [4, 'IV'],
        [1, 'I']
    ]
    let b = []
    while (num > 0) {
        for (let i = 0; i < a.length; i++) {
            if (a[i][0] <= num) {
                num -= a[i][0];
                b.push(a[i][1]);
                break;
            }
        }
    }
    return b.join('');

};